Revolving chair



Dec. 6, 1938. C; A PURDY 2,139,462

REVOLVING CHAIR Filgd March 5, 1938 Arm/Pm "30 spindle supporting members.

Patented Dec. 6, 1938 UNITED STATES PATENT OFFICE REVOLVING CHAIR Chester Purdy, -Hinsdale, Ill., assignor to Western Electric'Company, Incorporated, New York, N. Y., a corporation of New York Application March 5, 1938, Serial No. 194,048

6 Claims.

This invention relates to revolving chairs; and more particularly to revolving chairs having means for raising or lowering the seat portion of the chair. i

An object of the present invention is to provide an improved and simplified chair in which the seat portion may be rotated in normal service at a selected elevation and readily shifted to another desired elevation. 10 It is common practice inchairs having revolving seats, to provide some means whereby the height of the seat may be adjusted to suit the occupant. Early chairs of this type were provided with a threaded spindle on the seat which :15 engaged internal threads in a hub member ati 20 gaging threads on the spindle and hub lubricated properly under constant movement. In later constructions various mechanisms have been provided for supporting the seat rotatably at a fixed height and for changing the seat height 2.5 as required. This was usually accomplished by the use of a threaded spindle fixed to the seat and supported rotatably by adjustable members on the chair legs, .and changes in seat elevation were made by mechanical adjustment of the These constructions were relatively costly as they employed a plurality of machined and fitted parts and the manipulations involved in adjustment of the seat elevation often required the use of tools .andin 35 .scme cases the assistance of a mechanic. The present invention combines the advantages of the above structures by providing arevolving chair of simple construction in which no manual operation other than the rotation of the 40 seat is required to change its elevation. In one embodiment of the invention the chair seat is supported on the outer race of a ball bearing and the inner race of the bearing is fixed to a spindle which has a threaded lower portion in i 45 engagement with an internally threaded cylinder fixed to the chair legs. Projecting radially from the top portion of the spindle near the bearing is a pin which is adapted to engage a second pin mounted on the bottom of the seat as the seat is 50 rotated. The seat rotates freely on the ball bearing until the pin on the spindle engages the pin on the seat whereafter any continued rotation of the seat in the same direction causes the threaded spindle to turn in the cylinder to cf- 155 feet a change in the elevation of the seat. With this construction the seat height is readily adjusted by mere rotation of the seat and when a satisfactory seat elevation is established the seat can be rotated freely on the bearing at that height through an arc of about 330, which is ample for normal use, without efiecting any change in the seat height.

Following is a more detailed description of a specific embodiment of the invention taken in conjunction with the attached drawing, in which Fig. l is a side elevation of a chair embodying certain features of the invention;

Fig. 2 is an enlarged and partial view in section of the chair shown in Fig. 1 taken on the line 2--2 of Fig. 1, and

Fig. 3 is a sectional view of Fig. 2 taken on the line 3-3.

In the revolving chair shown in the drawing a wooden seat I0 is secured by any suitable means to a cast iron or steel seat plate II which is skeletonized to conserve material and minimize the chair weight. Secured to the seat plate is a formed. bracket l2 on which .an adjustable backrestl3 is supported. Depending from the bottom of the seat plate are two vertical flanges I4 which taper relatively from the plate periphery towards the center ofthe plate.

Fitted between these tapering flanges and secured to the seat plate is an anchor block l5 made of cold-rolled steel for securing a ball bearing Hi to the seat assembly. The anchor block has a uniform thickness and sides which conform to the taper of the flanges and engage the flanges to position the block accurately in assembly. There is a circular opening I1 in the block for encircling the ball bearing and a slot l8 extends from the opening to one of the parallel ends of the block. Due to the structure of the block, the portion of the block surrounding the opening is resilient so that the block can be readily clamped on the outer race I9 of the bearing by drawing together the end portions of the block adjacent to the slot. This can be accomplished with a screw 20 inserted in an enlarged shouldered bore 2| in the end portion of the 4!! block at one side of the slot and anchored in plate, the securing means being positioned to maintain the resiliency of the slotted end portions of the block. Referring to Fig. 2, the block and seat plate can be welded together at the lower or long end 32 of the block and the lower portions of the plate flanges adjacent to the long end of the block.

Secured to the inner race 25 of the ball bearing is a cylindrical spindle 26. The top end portion of the spindle is machined to a diameter slightly greater than the inner diameter of the bearing and then pressed into the bearing opening to join these members. The spindle has a threaded lower portion 21 supported in an internally threaded cylinder 28 which is fixed to the legs 29 of the chair with the threads on these members in constant engagement.

Fixed to the top portion of the spindle near and below the bearing is a radially extending spindle pin 30. Extending downwardly from the anchor block and secured thereto is a second or seat pin 3|.which is adapted to engage the spindle pin during rotation of the seat on the bearing.

With this construction the seat rotates freely on the ball bearing at any time that the two pins are out of contact because under these conditions movementof the spindle in the threaded cylinder on the legs is restrained by the relatively high frictional contact between the threads on these members. This permits the seat to be rotated freely on the bearing through an arc of about 330 without causing any rotation of thespindle in the threaded hub or resultant changes in seat elevation. This range of free movement approximates a complete revolution of the seat and is fully adequate for normal use where rotation is ordinarily restricted to about 180.

To change the elevation of the seat it is merely necessary to rotate the seat until the seat pin engages the spindle pin and then continue rotation of the seat which turns the spindle in the threaded cylinder and moves the spindle bearing and seat to another height as desired.

Because the described chair employs a simple construction and a minimum of component parts,

.it is light, economical to manufacture and easy to maintain. Because the seat is freely moveable on the bearing at a fixed elevation and can be readily adjusted by merely spinning the seat, the chair is highly useful for general service where more complex mechanisms are impractical.

Adaptations of the specific structure described herein are practical, and it is to be understood that the invention is limited only by the scope of the appended claims.

What is claimed is:

l. A revolving chair comprising a supporting means, an internally threaded member secured to said supporting means, a spindle having a threaded lower portion engaging the threads in said member, a bearing mounted on said spindle,

a seat rotatably supported on said bearing, a projection extending from the seat, and a second projection on the spindle for engaging the first projection during rotation of the seat and causing the spindle to turn in the threaded member.

2. A revolving chair comprising a seat, a plurality of supporting legs, a bearing mounted on the seat, an internally threaded hub member secured to the legs, a spindle having a threaded lower end portion engaging the threads in the hub and an upper portion freely moveable on said bearing, a pin projecting from the spindle, and a second pin projecting from the seat for engaging the pin on the spindle during rotation of the seat and causing the spindle to turn in the threaded hub thereby changing the elevation of the seat relative to the legs.

3. A revolving chair comprising a seat, a plurality of supporting legs, a ball bearing beneath the seat with the outer bearing race fixed to the seat, an internally threaded hub fixed to the legs, a spindle having a threaded lower end portion engaging the threads in the hub and an upper end portion secured to the inner race of the ball bearing, an elongated member projecting downwardly from the bottom of the seat, and a second elongated member projecting radially from the spindle for engaging the elongated member on the seat as the seat is rotated and causing the spindle to turn in the threaded hub to change the height of the seat.

4. In a revolving chair, a plurality of legs, an internally threaded cylinder fixed to the legs, a spindle having a threaded lower end portion engaging the threads in the cylinder and a cylindrical upper end portion, a ball bearing on the spindle with the inner race of the ball bearing fixed to the upper end portion of the spindle, a seat, means for securing the seat to the outer race of the bearing, a pin projecting downwardly from the bottom of the seat, and an arm projecting radially from the spindle in the path traveled by said pin when the seat is revolved on the bearing for causing the spindle to turn in the threaded hub and change the elevation of the seat relative to the legs.

5. In a revolving chair, a plurality of supporting legs, an internally threaded hub fixed to the legs, a spindle having a threaded lower end portion engaging the threaded hub and a cylindrical upper end portion, a ball bearing having its inner race secured to the upper end portion of the spindle, a seat, and a member on the seat for joining the seat to the ball bearing, said member comprising a central portion having an aperture for enclosing the bearing, spaced end portions adjacent to said aperture formed by a slot extending to the aperture, and means for varying the spacing of said end portions to clamp the member against the outer periphery of the ball bearing.

6. In a revolving chair, a plurality of supporting legs, an internally threaded hub fixed to the legs, a spindle having a threaded lower end portion engaging the threaded hub and a cylindrical upper end portion, a ball bearing having its inner race secured to the upper end portion of the spindle, a seat, a member on the seat for joining the seat to the ball bearing, said member, comprising a central portion having an aperture for enclosing the bearing, spaced end portions adjacent to the aperture formed by a slot extending to the aperture, and means for vary- .ing the spacing of the end portions to clamp the first pin and causing the spindle to turn in the threaded hub when the chair is revolved.

CHESTER A. PURDY. 

